Fluorescent lampholder with mounting clip



United States Patent 3,397,376 FLUORESCENT LAMPHOLDER WITH MOUNTING CLIP Andrew J. Gombar, South Norwalk, Conn., assignor to Kulka Electric Corporation, Mount Vernon, N.Y., a

corporation of New York Filed May 24, 1966, Ser. No. 552,476

8 Claims. (Cl. 339-56) ABSTRACT OF THE DISCLOSURE A lampholder assembly comprising a pair of lampholders for supporting a double-ended fluorescent lamp therebetween and connecting said lamp to a source of potential, wherein each lampholder is mounted for limited tilting movement on a support plate. A spring clip is mounted on each lampholder and has a leg extending along the base of the lampholder and projecting therefrom into engagement with the support plate for urging the lampholders toward each other so as to apply com- ;pressioned force upon the lamp mounted between the lampholders.

This invention relates to lampholders for fluorescent lamps, and more particularly to lampholders adapted to receive and hold the ends of a double-ended bi-pin fluorescent lamp.

The invention relates especially to the type of fluorescent lampholder known in the trade as a tombstone lampholder. Such lampholders are mounted with their bases flush against a fixture wall and with their body portions perpendicular to the body wall and are secured in mounted position spaced apart a distance corresponding to the length of the lamp. The lamp is mounted between the lampholders by inserting the lamp pins in slots in the lampholder bodies and then twisting the lamp so that the pins turn through sockets communicating with the entrance slots, with the pins engaging and being resiliently clamped by contact strips in the sockets.

' Tombstone lampholders of this type are normally mounted in inverted position in a ceiling fixture, that is with the lampholder bodies depending from the fixture wall so-that they open downwardly, and the lamp is usually inserted and removed from beneath the fixture. It frequently happens that the mounted lamp tends to rotate in'the lampholders due to vibration, loss of resiliency of the lampholder contacts and other causes, resulting in the lampholder pins disengaging from the lampholder contacts and the lamp falling from between the lampholders with possible injury to persons and property.

The principal object of the present invention is to provide a fluorescent lampholder assembly for bi-pin lamps having improved mounting means adapted to maintain the lampholders in position to exert compressional forces on the lamp and thereby retain the lamp securely in mounted position.

Another object of the invention is to provide a fluorescent lampholder assembly having improved mounting 'means enabling the lampholders to be quickly and conveniently mounted on a fixture.

A further object of the invention is the provision of a fluorescent lampholder assembly in which the lampholders are provided with improved mounting means adaptable for mounting upon fixture walls of varying thicknesses.

In accordance with the invention herein there is provided a lampholder assembly for bi-pin fluorescent lamps comprising a pair of lampholders adapted to be mounted in upstanding or depending position from a support plate or fixture wall. Each lampholder comprises a 'base and a perpendicular body portion, with a slotted portion located 3,397,376 Patented Aug. 13, 1968 between the base and body portion. The fixture wall or support plate is formed with a pair of recesses each sized to receive the slotted portion of one of the lampholders for mounting the lampholder on the plate for limited tilting movement of both lampholders toward each other. Each lampholder base is also formed with a slot receiving a spring clip having a leg which projects beyond the wall of the base in such a manner as to engage the surface of the support plate when the lampholder is mounted thereon. The spring clips bias the lampholders toward each other so as to apply compressional force upon a lamp mounted between the lampholders and thereby retain the lamp against accidental rotational movement 'and possible dislodging from the lampholders.

Additional objects and advantages of the present invention will become more apparent from a consideration of the following detailed description when taken in conjunction with accompanying drawings, in which:

FIG. 1 is an exploded view of one end of a fixture constructed according to the present invention, with parts broken away:

FIG. 2 is a front elevational view of the lampholder shown in FIG. 1, in mounted position upon a fixture wa1l,;

FIG. 3 is a side elevational view of the lampholder shown mounted on a fixture wall, with portions shown in section, and showing one end of 'a lamp about to be inserted in the lampholder; and

FIG. 4 is a side elevational view of a fixture mounting a pair of opposed lampholders of the present invention, with a lamp mounted therebetween.

The lampholder assembly of the present invention is designated generally by the reference numeral 10 in FIG. 4 and includes a supporting fixture plate 12 which mounts opposed lampholders 14 and 16. The lampholders 14 and 16 are identical in construction. Therefore, only the lampholder 14 will be described in detail, it being understood that corresponding elements of the lampholder 16 will be designated by the same numeral.

Lampholders 14 and 16 are of the tombstone type, being mounted perpendicularly to 'a fixture wall and upstanding or depending therefrom. Lampholder 14, for example, comprises a hollow flat base 18 and an integral flat body portion 20 extending perpendicularly from one end of the base so that the base 18 projects "forwardly of the body portion 20. The body portion 20 is formed with a front wall 22, 'a rear wall 24, a top wall 25, and opposed side walls 26 and 28. The base is provided with a top wall 30, a bottom wall 32, opposed side walls 34 and 36 and a front wall 38.

Provided in the body portion 20 is a socket designated generally by the numeral 40. The socket 40 is defined by a circular aperture 42 in the front wall 22, and communicating with socket 40 is a passage 44 which opens through the top wall 25 and front wall 22 of the body portion 20. As shown in FIG. 2, the outer edge of the passage 44 is wider than the inner edge to facilitate the insertion of a fluorescent lamp therein in the manner noted below. Extending forwardly from the rear wall 24 are opposed semi-circular members 46 which are spaced apart to de fine a passage 48 therebetween. Surrounding each one of the semi-circular members 46 is the end portion of a respective contact strip 50 having a concave or bowed pin-retaining portion 51 adjacent the respective member 46. The contact strips 50 extend through the interior of body portion 20 in the usual manner to the base 18 where they are secured in position and adapted to be electrically connected to lead wires in turn connected to a power source. For this purpose, the front wall 38 of the base 18 is provided with a plurality of keyhole-shaped slots 52 sized to receive the ends of such lead wires for connecting the respective contact strips 50 with a source of potential.

The lampholders 14 and 16 are adapted to receive and support a lamp therebetween, such as the lamp L shown in FIGS. 3 and 4. These lamps are conventionally provided with opposite end sections 54, each having a pair of laterally-projecting contact pins 56.

FIG. 4 shows the manner in which the lampholder assembly is arranged to receive and support the lamp L. The lampholders 14 and 16 are shown mounted in inverted position upon the fixture wallor supporting plate 12, as would be the situation in the case of a ceiling fixture, although in some installations the lampholders may be mounted vertically upright or horizontal. As with all lampholders of this type, the lampholders 14 and 16 are spaced apart sutficiently that the distance between their front walls 22 is substantially equal to or slightly greater than the length of the lamp L between the faces of the end sections 54, but less than the distance between the tips of the pairs of pins 56 at the opposite ends of the lamp. The lampholders are normally mounted in such spaced relationship upon the supporting plate by screws or bolts. The conventional manner of mounting a lamp L in such a fixture arrangement is to align the pair of pins 56 at each end of the lamp L with the axis of the passage 44 of the corresponding lampholder, and moving the lamp upwardly so that the upper pin moves through the passage 48 between the semi-circular members 46. The lamp L is then rotated ninety degrees so that the pins of each pair are located in a horizontal plane. In this position, the pins 56 will be in alignment with the concave portions 51 of the respective contact strips 50, and will be located between these concave strip portions 51 and the semi-circular members 46. The resilience of the metal contact strips 50 will normally press the pins against the members 46 to hold the lamp in mounted position between the lampholders. However, vibration, jarring or any relative movement between the lamp L and an associated lampholder may cause the lamp L to rotate relative to the lampholder thereby freeing the pins 56 from their locked position thereby to allow the lamp L to fall out of the lampholder.

In order to prevent relative movement between the lamp and the lampholders the side walls 26 and 28 of the supporting arm 22 of the lamp holder 14 are provided with opposed lateral extensions 60 and 62 defining shoulders which are spaced from the bottom wall 32 of the base 18 to form respective slots 64 and 66 therebetween. A supporting plate 12 having the desired length to accommodate the particular lamp L to be mounted is selected. Provided in the edge of the supporting plate 12 is a rectangular recess 68.

The lampholder body portion 20 is adapted to be received within the recess 68 with the portions defining the side walls of the recess 68 slidably received in the respective slots 64 and 66. As shown in FIG. 3, the height of each of the slots 64 and 66 is in excess of the height of the supporting plate 12. Accordingly, the lampholder 14, as well as the identical lampholder 16, will have limited pivotal movement with respect to the supporting plate 12. That is, the lampholders 14 and 16 may be pivoted toward one another until the bottom front edges of the slots 64 and 66 engage the underside of the support plate 12, as indicated by the solid line drawing of the lampholder 14 in FIG. 3. On the other hand, the lampholder 14 may be pivoted until the bottom surface 32 of the base 18 engages the support plate 12, as shown in FIG. 4, whereby the body portion 20 moves outwardly to the dotted line position shown in FIG. 3.

As a feature of the present invention, biasing means are provided to bias the lampholders 14 and 16 to the solid line position shown in FIG. 3, wherein the lampholder body portions 20 are inclined toward each other and toward the center of the supporting plate '12. More specifically, an open ended slot 70 is centrally provided 4 in the front wall 38 of the base 18. Received in slot is a biasing member in the form of a spring clip 72. The clip 72 has a U-shaped portion 74 terminating in a depending leg 76. The clip is mounted by pressing the U-shaped portion 74 into slot 70, with the arms of the U-shaped portion 74 in tight frictional engagement with the walls defining the upper and lower portions of said slot 70. The leg 76 is sized and positioned to extend slightly below the wall 32 of the lampholder'basefls. Additionally, the free edge of the leg 76 is provided with serrations at 78. The spring clip biasing member 72 may be fabricated from a spring steel or the like.

In assembling the fixture of the present invention, a lampholder such as the lampholder 14 is inserted into the recess 68 of the preselected supporting plate 12 with the portions of supporting plate defining the side walls of the recess 68 being received within the respective slots 64 and 66 in the lampholder 14. Since the leg 76 of the spring clip 72 extends beyond the wall 32 of the base 18, the serrated edge 78 of the clip leg 76 will engage the facing surface of the supporting plate 12. The lampholder 14 is biased forwardly in the recess 68 by the spring clip until the inner edge of the recess 68 is slightly spaced from the front wall 22 of the lampholder body portion 20. The serrated edge 78 provides a tight frictional engagement between the supporting plate 12 and the lampholder 14 which prevents relative sliding movement between the two elements after the lampholder has been set in place. Additionally, since the leg 76 extends beyond the wall 32 of the base 18, the lampholder bodies 20 of the lampholders 14 and 16 will be biased toward each other; the orientation of the lampholder 14 being shown by the solid line position of FIG. 3.

When it is desired to insert a lamp L between the lampholders 14 and 16, the lamp pins are inserted into the passages 44 of the respecitve lampholders, as previously described, and the lamp moved upwardly until the pins are fully received in the sockets 40. The lam-p is then rotated in the usual manner until the pins engage and are retained by the contact strip portions 51. As the lamp is moved upwardly between the lampholders to move the pins into the sockets, the end sections 54 of lamp L engage the front walls 22 of the respective lampholder bodies 20, and press the lampholders apart, causing both lampholders to pivot toward their upright positions, perpendicular to the support plate 12. When the lamp L is fully inserted and is released, the spring clips 72 tend to pivot the lampholders to their tilted positions, and thereby bias the lampholder bodies into tight frictional engagement with the end sections of the lamp L, thereby preventing any accidental rotation of the lamp relative to the lampholders. Unintentional dislodging of the lamp with its consequent breakage and damage, is thereby minimized.

It will be appreciated that the spring clips 72 in addition provide an automatic frictional mount for the lampholder upon the support plate, eliminating the necessity for providing or using the usual screws for this purpose. Further, the spring clips enable the same lampholder to be mounted upon fixture walls or support plates of varying thicknesses. While the lampholder slots 64, 66 may be sized to receive snugly a plate of .62 inch thickness, for example, plates of lesser standard thicknesses such as .54 inch or .40 inch may be employed, the resilient spring clip compensating for the difference in thickness and holding the lampholder immovably on the support plate under spring tension.

While a preferred embodiment of the invention has been shown and described herein, it will be obvious that numerous omissions, changes and additions may be made in such embodiment without departing from the spirit and scope of the present invention.

What is claimed is:

1. A lampholder for supporting and for connecting a double-ended fluorescent lamp to a source of potential comprising a base member having a flat bottom wall adapted to overlie a support plate formed with an openended recess therein, a front wall upstanding from and perpendicular to said bottom wall, and a pair of side walls, a body portion depending perpendicularly from said base member bottom wall, a socket in said body portion adapted to receive the terminals of a lamp therein, contact means in said socket adapted to engage the terminals of the lamp in firm frictional engagement to connect the terminals with a source of potential, slots at the opposite sides of said lampholder sized to receive the edges of the supporting plate adjacent said recess when the lampholder is brought to a mounted position in which the lower end of said body portion is located within said open ended recess and said base member bottom wall overlies said supporting plate, said slots being of greater depth than the thickness of said supporting plate to movably mount said lampholder on the plate for tilting movement of said body portion between a first position wherein said body portion is inclined toward the center of the plate and a second position wherein the body portion is substantially normal to said plate, and biasing means on said lampholder sized and positioned to engage the supporting plate to bias said lampholder toward the first position, said biasing means comprising a spring clip member mounted on said base member and having a depending leg extending along and substantially parallel to the front wall of said base member, said depending leg having a free terminal edge normally projecting below the plane of said base member bottom wall, said projecting terminal edge engaging said supporting plate in the mounted position of the lampholder to urge the latter toward its first position under the biasing force of said spring clip member.

2. A lampholder according to claim 1, in which said body portion is provided with opposed lateral extensions in spaced relation to said base to define said slots therebetween.

3. A lampholder according to claim 1, which also includes friction means on the free terminal edge of said leg for 'frictionally engaging the supporting plate to prevent relative sliding movement between the plate and said lampholder, and constituting self-contained means for securely mounting said lampholder on said supporting plate.

4. A lampholder according to claim 1, in which said base member is provided with a slot in the front -wall thereof, said spring slip member comprising a strip of resilient material formed with a U-shaped bight extending perpendicularly from said depending leg, said bight being frictionally received in said front wall slot.

5. A lampholder for supporting and for connecting a double-ended fluorescent lamp to a source of potential comprising a base member, a body portion extending perpendicularly from said base member, a socket in said body portion adapted to receive the terminals of a lamp therein, contact means in said socket adapted to engage the terminals of the lamp in firm frictional engagement to connect the terminals with a source of potential, slots in said lampholder adapted to receive a portion of a supporting plate therein to movably mount said lampholder on the plate for tilting movement of said body portion between a first position wherein said body portion is inelined toward the center of the plate and a second position wherein the body portion is subsatntially normal to said plate, and biasing means on said lampholder sized and positioned to engage the supporting plate to bias said lampholder toward the first position, said base member being provided with an open-ended passage, said biasing means comprising a strip of resilient material received in said passage and having a depending leg sized to extend below the lower surface of said base member, and a serrated edge on the bottom of said leg for frictionally engaging the supporting plate to prevent sliding movement between said lampholder and the supporting plate.

6. A lampholder assembly for mounting a fluorescent lamp having a head at each end thereof and terminals carried by said heads, said assembly including a supporting plate having recesses at the ends thereof, a pair of opposed lampholders mounted in the respective recesses, each of said lampholders comprising a base member having a bottom wall adapted to overlie said supporting plate, and a front wall upstanding perpendicularly from said bottom wall, a flat body portion extending perpendicularly from the bottom wall of said base member, a socket in said body portion adapted to receive the lamp terminals therein, contact means in said socket adapted to engage the terminals of the lamp in tight frictional engagement to connect the mounting means with a source of potential to illuminate the lamp, slots in said lampholder sized to receive the edges of said supporting plate adjacent said recess therein, said slots being of greater depth than the thickness of said supporting plate to movably mount said lampholders on the plate for limited pivotal movement between a first position wherein said lampholders are in clined towards each other and a second position wherein said lampholders are substantially parallel to each other; and biasing means on said opposed lampholders sized and positioned to engage said supporting plate to bias said lampholders to the first position, whereby said lampholders exert a compressive force on a lamp mounted therebetween, said biasing means comprising a spring clip member mounted on said base member and having a depending leg extending along and substantially parallel to the front wall of said base member, said depending leg having a free terminal edge normally projecting below the plane of said base member bottom wall, said projecting terminal edge engaging said supporting plate in the mounted position of the lampholder to urge the latter toward its first position under the biasing force of said spring climp member.

7. A lampholder assembly according to claim 6, wherein each of said base members is provided with a slot in the front wall thereof, said spring clip member comprising a strip of resilient material formed with a U-shaped bight extending perpendicularly from said depending leg, said bight being 'frictionally received in said front wall slot.

8. A lampholder assembly according to claim 7, in which each of said depending legs has a serrated edge on the 'free end thereof, for frictionally engaging said supporting plate to prevent sliding movement bet-ween said lampholder and the supporting plate and for providing pivotal movement between said lampholders and said supporting plate.

References Cited UNITED STATES PATENTS 2,306,908 12/1942 Stitfel 339--56 2,513,832 7/1950 Weisberg 339-56 2,531,533 11/1950 Shaw 33956 3,138,418 6/1964 Dazley et al. 339-50 MARVIN A. CHAMPION, Primary Examiner.

JOSEPH H. MCGLYNN, Assistant Examiner. 

